Filter cap for vacuum cleaner motor



Sept. 7, 1965 s. HOWARD 3,204,395

FILTER CAP FOR VACUUM CLEANER MOTOR Filed May 8, 1963 I I i\ I I 5 l IINVENTOR. 5w. flow/yep Warm United States Patent 3,204,395 FILTER CAPFOR VACUUM CLEANER MOTOR Sol Howard, Brooklyn, N.Y., assignor to Mil-AnMfg. Corp., a corporation of New York Filed May 8, 1963, Ser. No.278,826 1 Claim. (Cl. 55-505) The present invention relates generally tovacuum or suction cleaners and in particular to a novel secondary filtertherefor.

A conventional vacuum cleaner comprises a housing or cannister having aninlet air opening and an outlet air opening. A fan motor is mountedwithin the housing to provide for suction air fiow therethrough. Afilter bag or the like is contained within the housing adjacent to theinlet opening to remove dirt and debris from the air stream which flowsthrough the filter bag, past the fan motor and out through the airoutlet opening. It is known in the prior art to interpose a secondaryfilter between the primary filter and the fan motor to assure thesubstantially complete removal of debris from the air stream flowingover the fan motor and to protect the latter in the event of a ruptureof the primary filter or in case of inefficient operation thereof orfiltration thereby. However, the secondary filters of the prior art arerelatively complex and inefficient. Moreover, they cannot be readilyremoved and replaced.

In view of the foregoing, it is an object of the present invention toobviate the foregoing disadvantages of prior art secondary filters.

It is another object of the present invention to provide a secondaryfilter which, although of generally simplified construction, is highlyefficient in operation and which can be removed and replaced in a verysimple manner and in a very short time and which does not require anydegree of mechanical skill or aptitude to effect said removal andreplacement.

It is a further object of the present invention to provide a secondaryfilter in the form of an open-work dome shaped cap provided with acollar which mounts a filter element in position to engage saidopen-work dome to prevent the passage of foreign material therethrough.

It is a still further object of the present invention to mount thefilter on a fan motor end cap provided with a central aperture and tospace the filter element therefrom so as to define an enlarged air flowchamber between the filter element and the end cap.

Other and further objects and advantages of the presnet invention willbe readily apparent to those skilled in the art from a consideration ofthe following specification taken in connection with the appendeddrawing.

In the drawing which illustrates the best mode presently contemplatedfor carrying out the invention:

FIGURE 1 is a side elevation of a vacuum cleaner provided with asecondary filter pursuant to the present invention, parts being brokenaway and shown in section for purposes of illustration;

FIGURE 2 is a view, on an enlarged scale, taken in the direction ofarrows 22 in FIGURE 1;

FIGURE 3 is a sectional exploded view taken on the line 33 of FIGURE 2;

FIGURE 4 is a view similar to FIGURE 3, with the parts being shown intheir assembled relation;

FIGURE 5 is a plan view of the filter element; and

FIGURE 6 is a sectional view taken on line 66 of FIGURE 4, with a partbroken away for purposes of illustration.

Referring now to the drawings in detail, there is shown a suction orvacuum cleaner 10 which is provided with a cylindrical body or cannisterenclosure 12. The cannister 12 is open at both ends thereof. One end ofthe 3,294,395 Patented Sept. 7, 1965 ice cannister is closed by a cover14 which is hinged thereto, as at 15. A latch member 16, pivoted to thecannister as at 17, ,releasably locks the cover 14 in the operativecondition thereof shown in FIGURE 1. A central air inlet opening 18 isdefined in the cover 14 for air flow into the cannister 12 in thedirection of arrow 19. An air pervious filter bag 20 is mounted inconventional fashion within the cannister. The open end of the filterbag is engaged on a nozzle 21 which extends into the cannister from theair inlet opening 18 in the cover 14.

The cannister is provided with a pair of conventional skids 22 mountedon the lower surface thereof and with a conventional carrying handle 24provided on the upper surface thereof. An ON-OFF switch 26 is providedadjacent to the handle. The other open end of the cannister is closed byan outlet end cap 28 which is provided with a conventional central airoutlet opening (not illustrated) through which the air flow issues fromthe cannister, as indicated by the arrow 29.

A motor fan assembly 30 is mounted within the cannister 12 between theend closure cap 28 and the bottom of filter bag 20. Said assemblyincludes a motor fan housing 32 for a conventional motor fan (notillustrated). The operation of the fan is controlled by switch 26. Thefan housing is provided with an end plate or cap in which there isdefined a central air-inlet aperture 36.

Pursuant to the present invention, provision is made for a secondaryfilter means or filter cap assembly 34. As here shown, the filter capassembly comprises a filter cap 38, a secondary filter element 40 and asecuring element 42 to removably secure said filter element in said cap.

The filter cap 38 is a generally cup-shaped shell formed of any materialsuitable for the punpose, preferably a suitable plastic material. Saidfilter cap comprises a cylindrical collar 44 which is integral with anopen-work or frame dome-shaped cage or head 46. At the inner surfacethereof, the collar is provided with an integral circumferentialshoulder 48, and at the outer surface thereof, the collar is providedwith integral reinforcing ribs 50 which extend into the dome 46 to acentral integral disc 52 thereof which is provided with a centralaperture 54. The filter cap 38 is provided with a filter element whichoverlies the cage portion thereof. In the (preferred form of theinvention herein illustrated the filter element overlies the interiorsurface of the cage, as will be more particularly hereinafter pointedout. It will 'be understood however that the disposition of the filterelement may also be along the exterior surface of the cage, although insuch arrangement certain of the advantages of the invention may not berealized.

The filter element 40 is in the form of a disc which is provided alongits circumference with notches or gores 56. The disc 40 is provided alsowith a central aperture 58. The disc is formed of any suitable airpervious filter material, preferably a matte formed of glass fibers. Itwill .be understood that the diameter of the filter element 40 exceedsthe inner diameter of the filter cap.

In forming the filter cap assembly 34, the filter disc 40, which has adesired degree of relative stiffness, is urged into the collar 44 offilter cap 38 toward the frame dome 46 thereof. Due to the fact that thediameter of the disc is larger than the inner diameter of the filtercap, the disc will bend inwardly of and concentrically with itscircumferential periphery. Said bending is facilitated by the V-shapednotches 56 which prevent the formation of wrinkles in the disc. The discis urged into engagement with the dome, as best shown in FIGURE 4. Whenso engaged, the circumferential peripheral edge of the disc is engagedor seated on the shoulder 48 of collar 44 .which serves as a detent forthe disc. In order to secure the disc element in snug engagement withthe inner surface of the open fria-me domed cage, the previouslyidentified clasp 42 is inserted through the cage aperture 54 and thefilter disc aperture 58 and the twin legs 60 of the clasp are spreadapart to retain the disc snugly against the inner surface of the dome,as shown in FIGURE 6. t

The filter cap assembly 34 is mounted on the housing end plate cap 33,as best shown in FIGURE 4. The collar 44 is urged into frictionalengagement on to the circumferential wall of end cap 33 until theinternal shoulder 48 engages the end cap, as illustrated. An air chamber62 is defined between the confronting surfaces of the end cap 33 and thefilter cap assembly 34. This chamber aids the air flow through thefilter disc since the space defined by the chamber permits the air toflow into the chamber rather than directly into the restricted opening36 in the end cap.

It will be apparent that during operation of the vacuum cleaner 10, thefan motor thereof causes an air flow through cannister 12 in thedirection of the arrows 19 and 29. The air is initially filtered as itpasses through the filter bag 20 and is filtered a second time as itpasses through the filter element 40, the open frame dome 46 providingno impediment for the air flow. The secondary filter 40 serves to removeany remaining grit in the air stream so as to protect the fan motor. Inthe case of the rupture of the filter bag 20, the filter disc 40 is thesole source of protection for the fan motor.

While I have illustrated and described the presently preferredembodiment of my invention, it will be understood that various changesand modifications may be made therein, without however departing fromthe inventive concept thereof as set forth in the appended claim.

1 claim:

A filter cap assembly for a vacuum cleaner motor housing having an endplate provided with an air inlet port extending the-rethrough, said capcomprising a cup shaped shell having a collar and a dome provided onsaid collar, said collar being adapted to encompass and frictionallyengage said end plate when disposed thereon, said dome having a disk atthe apex thereof and a plurality of circular ribs extending in spacedconcentric relation from said disk to said collar, and a plurality ofarcuate ribs radiating from said disk to said collar transversely ofsaid circular ribs, said radiating ribs being integral with saidcircular ribs as well as with said disk and said collar, acircumferential ledge provided on the inner surface of said collar, onesurface of said ledge constituting a detent for the end plate, and afilter element disposed within said shell in abutment with the innersurfaces of said disk and said ribs, said filter element having acircumferential peripheral edge, the. opposite surface of said led-geconstituting a seat for said peripheral edge, and a securing elementextending through said disk and the adg'acent portion of said filterelement for securing the latter in position at the inner surface of saiddome.

References Cited by the Examiner UNITED STATES PATENTS 2,245,760 6/41Clements 15-327 X 2,576,726 111/5 1 Segesman 372 X 2,586,935 2/52 Gerson55-486 X 2,815,090 l-2/57- Humphrey 55-378 X 3,031,826 5/62 Brimberg etal. 55492 3,050,191 8/62 Gillick et al. 2 10-485 3,075,334 1/63 Nutting55-357 3,082,587 3/63 Brimberg 55-495 ROBERT F BURNETT, PrimaryExaminer.

